Prior to one or more of the embodiments outlined in the present invention, any type of brush holder utilizing a constant force spring and which was internal to the electric motor, generator, or actuating device (i) consisted of several different complex parts which were fixed in location and position; (ii) was severely limited in range of applicability; (iii) was costly to manufacture; (iv) did not properly receive, position, engage, and actuate the constant force spring; (v) was limited to the utilization of only one spring pressure; (vi) was limited to the utilization of only one size spring; (vii) was limited to only one size, length, or style of carbon brush; and (viii) was not easy to assemble, repair, replace, or maintain.
Since it was very costly to manufacture a brush holder utilizing a constant force spring and which was internal to the electric motor, generator, or actuating device, the range of applicability of such prior art devices was severely limited. One reason for this is due in part because the prior art does not properly receive, position, engage, or actuate the constant force spring so as to optimize its benefits by applying a constant force to the carbon brush. In addition, the prior art does not allow the interchange of different constant force springs of varying pressures and sizes and/or allow different lengths and sizes of carbon brushes. A true constant force was never achieved because the coils of the constant force spring were not properly received, positioned, engaged, and actuated. The prior art typically engaged the coils of a constant force spring by positioning them against a flat planar surface, the result of which was that the contact point was a tangent. Because the point of contact and engagement was a tangent, the constant force spring was not able to consistently achieve its full potential specified pressure nor was it able to achieve a true constant force. The force of the spring would not be constant, but rather, would vary throughout the range of motion, thus negating the well-known advantages of using a constant force spring. This would lead to less than optimal performance, decreased carbon brush life, more frequent and costly replacement of the carbon brushes, and increased maintenance on the electric motor, generator, or actuating device.